It is just another added layer of providing additional mitigation for the safety of our students and our staff as we think about returning to the hybrid model for in person learning, Superintendent Barbara Malkas told the School Committee on Tuesday. Pool testing means mixing samples from a group, such as a classroom, and testing for COVID-19 antigens. A negative test means the entire group is clear; a positive test means that each person in the pool would have to follow up with rapid result testing. Within 15 minutes, we would know who the positive individuals are because they would need to isolate and we would need to do our contact tracing, Malkas said. And we d have to make sure that anybody else in that particular pool was asymptomatic and therefore clear to resume learning and instruction.